Transmitter attachment and release methods for short-term shark and stingray tracking on coral reefs

This study details a simple and cost-effective means of attaching acoustic transmitters to coral reef sharks and stingrays, which potentially allows for retrieval and reuse on completion of tracks. Between 2008 and 2011, galvanised timed releases were trialled in both static field tests and on blacktip reef sharks Carcharhinus melanopterus, cowtail Pastinachus atrus, and porcupine Urogymnus asperrimus rays in Coral Bay (?23°08′41″, 113°45′53″), Western Australia. The timed releases remained attached to animals for the duration required for tracking and in four out of five deployments transmitters were recovered after release from the animals. The use of modified Rototags for sharks and stainless steel darts for stingrays allowed rapid and effective attachment to animals, with limited impact on their welfare in the short term. External attachment for short-term tracking of coral reef-associated elasmobranchs should be considered as a complementary option to internal placement of transmitters in animals either by surgery or by ingestion.